Tecnologia de duplo haploide na determinação da herança da resistência à podridão de colmo (Fusarium verticilioides) em linhagens de milho

Abstract

Were used in the study four populations synthesized by crossing two contrasting inbred lines as resistance to F.verticilioides. To obtain haploid inbred lines of these populations were crossed with haploid inducer, the haploid lines were then duplicated and selfed, and the seeds harvested were the of origin of the inbred lines used in the study. Seventy days after sowing the inbred lines were inoculated with a suspension of spores of the pathogen in F.verticilioides concentration of 2 106 spores and 70 days after inoculation the ears were harvested and weighed and stalks were collected, weighed and measured in length and diameter and longitudinally sectioned for evaluation of symptoms, which were also the lengths of the lesions measured. They were estimated to phenotypic, environmental variances, full genotypic and between and within families, as well as heritability and additive variance and dominance. The variance due to dominant genetic effects was greatest magnitude, and the heritability in the narrow sense was 0.28. The observed frequency distribution may indicate epistatic effects involved in the genetic control of resistance to F.verticilioides. The biggest gains expected with the selection were achieved with the use of selection among families and mass selection.